What I'd say you should work on, is flow. You have basic movements down, so I think you could move into more complicated stuff, and make your animations delicious to the eye.
Right now, I see a couple of bad things:
First off, that double framing is a pain in the ass to look at. Never put in double framing just to enhance a powerful move. Use tremors or flashes or something, not df'ing.
To comment your newest animation, I honestly hated that slide/fly/run/thing or whatever it was meant to be. It looked absolutely out of place and weird. Suddenly he was just sliding across the screen, with no momentum or anything behind it.
Now for some more positive things :D
As I said, your movements are really good. I liked the kicks and the punch, they were nicely pulled off. Just remember that a kick isn't only about the leg. Remember to keep the whole body dynamic throughout every single movement.
Those simple smoke rings or whatever really added to the animation, good job man
As I said, I think you should work on flow. Right now, it's very stop-and-go (partially because of the df'ing of course). You need to practice having each movement flow into eachother, to make ONE big movement, instead of lots of smaller movements.
All this might be a bit much to swallow in one bite, please ask me if you need any additional help :)